Abstract: In view of the difficulty of firefighters' search and rescue due to the extremely low visibility in the dense smoke environment of fires, we proposed a fire penetration and smoke detection technology based on laser range gate imaging, and carried out physical experiments on imaging through wood pallets, n-heptane fires and smoke in confined spaces, which can image through 1.5 m longitudinal flame and improve the visibility in dense smoke environment by 3 times, solving the current problem that fires and smoke cannot be penetrated due to surface/interface reflection and serious backward scattering. Based on the experimental results, the application prospect of laser range gate imaging in firefighting visualization reconnaissance and rescue is discussed, and the future development direction of this research field is further clarified. The future development of fire reconnaissance and rescue equipment based on laser range gate imaging technology provides "perspective eyes" for fire rescue personnel, which is expected to effectively improve the fire control, rapid internal attack and personnel rescue capabilities in the initial battle and night environment.

Key words:  imaging through fire, imaging through smoke, fire reconnaissance, laser, laser range gate imaging